Resultados no grupo de tratamento:
\[\mathbb{E}[Y_{ist}|s = \text{Nova Jersey}, t = \text{Fev}] = \gamma_{NJ} + \lambda_{Fev}\]
\[\mathbb{E}[Y_{ist}|s = \text{Nova Jersey}, t = \text{Nov}] = \gamma_{NJ} + \lambda_{Nov} + \color{#d90502}\delta\]
\[
\begin{align}
\mathbb{E}[Y_{ist}|s &= \text{Nova Jersey}, t = \text{Nov}] - \mathbb{E}[Y_{ist}|s = \text{Nova Jersey}, t = \text{Fev}] \\
&= \gamma_{NJ} + \lambda_{Nov} + \delta - (\gamma_{NJ} + \lambda_{Feb}) \\
&= \delta + \underbrace{\lambda_{Nov} - \lambda_{Feb}}_{\text{tendência temporal}}
\end{align}
\]